In 2012, owing to a new reapportionment method, some incumbent members chose to run in differently numbered districts (typically within a similar geographic region, with some changing their residence) and owing to a new open primary system, some incumbents were placed against opponents of their own party in the general election. For details concerning these changes and the specific effects upon the 2012 election see Politics of California.

Acest format explică folosirea CULORILOR și ABREVIERILOR aplicabile membrilor CongresuluiStatelor Unite ale Americii.
This is a key to party COLORS and ABBREVIATIONS for Members of the U.S. Congress.Abrevierea numelor partidelor și/sau a numelor complete sunt folosite pentru acces "universal".Party abbreviations or full names are retained for universal visual access.